1. Field
Example embodiments relate to a method of manufacturing a Group III-nitride heterojunction structured device, for example, a selective low-temperature ohmic contact formation method for a Group III-nitride heterojunction structure.
2. Description of the Related Art
A Group III-nitride heterojunction structured device stands out in the field of electric power or optics. The Group III-nitride heterojunction structured device is useful for embodying a power device or LED (light emitting device) that may discharge a high current and support a relatively high pressure.
Therefore, with the recent acceleration of research and development and commercialization of photovoltaics, electric vehicles, and LEDs, there is increasing demand for studies and commercialization of the Group III-nitride heterojunction structured device.
However, because an ohmic contact metal layer is formed at a relatively high temperature of about 800-900° C. according to thus-far developed manufacturing methods of the Group III-nitride heterojunction structured device, the gate insulating layer exposed to a relatively high temperature process may be crystallized and/or dehydrogenated, thereby deteriorating device characteristics.
Furthermore, according to the currently used manufacturing method of the Group III-nitride heterojunction structured device, a gate electrode is formed using gold (Au) and requires a lift-off process, which is expensive and has undesirable etching characteristics, and thus has lower reproducibility. Accordingly, economic feasibility and reproducibility of the process are relatively low.